The Trishuli River () is one of the major tributaries of the Narayani River basin in central Nepal. The river is formed by the merger of Kyirong Tsangpo and Lende Khola originating in Gyirong County of Tibet, which join together near the Rasuwa Gadhi on the Nepal–Tibet border. The valley of the river provided the traditional trade route between the Kathmandu Valley and Tibet. Etymology The Trishuli is named after the trishula or trident of Shiva, the most powerful god in the Hindu pantheon, There is a legend that says high in the Himalayas at Gosaikunda, Shiva drove his trident into the ground to create three springs – the source of the river and hence its name Trisuli. Course The sources of the Trishuli River lie in the Pekhu Kangri range (called Langtang Himal in Nepal) in the Kyirong County in Tibet. Two major rivers Kyirong Tsangpo (or Kerung Khola) and Lende Khola merge near the Rasuwa Fort at the Nepal border to form the Trishuli river. Kyirong Tsangpo has a large basin extending beyond the town of Dzongka and numerous streams forming it: Zarong chu, Gyang chu, Prongda chu, Ublung chu, Tsalung chu, Ragma chu etc. After Ragma, it passes through a lush green alpine "Kyirong Valley" (elevation 2700 m) with several villages and the Kyirong Town. Afterwards it enters a deep gorge before reaching the Rasuwa Fort. The last stretch of the river is used as part of the Nepal–China border. Lende Khola has two further tributaries originating in Langtang Himal, viz., Richong Chu and Chusumdo Tsangpo, the latter again forming part of the Nepal–China border. Even though the Trishuli river is physically formed at the Rasuwa Fort, it is not officially called so at this stage. It is referred to by the generic name of "Bhot Koshi" ("the river from Tibet"). It is called Trishuli Ganga after receiving the Trisuli Khola stream originating in Gosainkunda near Dhunche. This would make Gosainkunda the official source of the river, and the river from Tibet a tributary. Tributaries Tadi Khola and Likhu Khola join Tishuli near the city of Bidur. The valleys of these rivers provide a link-up to Kathmandu via the pass of Badh Bhangyang. These valleys made up the traditional route between Kathmandu and Tibet. Procceding further, Trishuli joins the Narayani River at Devghat. Narayani flows south into India and joins the Ganges. Basin data More than 60